Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent, distressing, and interfering condition that affects between 2% and 6% of adolescents. Although medications have been widely used as an effective treatment for many years as the sole treatment for ADHD, for many, clinically significant and interfering continued symptoms remain. Even after medication treatment, adolescents still experience residual ADHD symptoms and continue to have problems with inattention, concentration, disorganization, and other symptoms. However, research suggests that adolescents who have received some benefit from medication treatment can then experience further symptom reduction from participation in skills-based cognitive behavioral therapy. This study, adapted from a similar research study for adults with ADHD, will examine whether cognitive behavioral therapy (CBT) plus medication is more effective at treating ADHD than medication therapy alone in adolescents with ADHD.